The Simpsons Movie? D’oh!

After 18 years, the cartoon family Simpson finally made it to the big screen. Considering the $500 million worldwide gross, I guess they were long overdue.

“The Simpsons” got its start in 1987 as a series of cartoon shorts intended to satirize family sitcoms such as “The Cosby Show.” It first appeared as interstitials on “The Tracy Ullman Show.” After three years, it got its own primetime slot on Fox and has since become the longest-running American cartoon series in history. Ironically, it has also become the longest-running family sitcom.

For their trip to the big screen, the Simpson family needed a big plot. And what’s the biggest topic in the world (literally) at the moment? Why, global warming. A subject ripe for the Simpsons’ brand of simplistic sarcasm.

The town of Springfield has a pollution problem. It’s so bad, when the rock band Green Day does a concert on a barge in the middle of their lake, the barge rots out underneath them. Steps are taken to clean up the lake, but Homer and his new pet pig undo them, creating a major ecological disaster. Then the federal government steps in to prevent the problem from spreading. This irks the town considerably, especially when they find out who is responsible for their woes.

If that’s not enough plot details for you, sorry. “The Simpsons” aren’t really about plot details; the genius is in the little things. Like Lisa’s lecture to the citizens of Springfield about pollution issues, titled “An Irritating Truth.” Or Bart’s chalkboard gag, which states, “I will not illegally download this movie.” Or Homer walking his new pet pig on the ceiling, singing “Spider-pig, Spider-pig. Does whatever a spider-pig does.”

It’s one of those iconic shows, like “Star Trek” or “Seinfeld,” where people remember little things the characters have said or done. But since this is for the big screen/private home viewing, there are a few things going on that can’t be done on television. Bart’s nude skateboard ride, for example. Or Marge’s anguished admonition to Homer and Bart near the film’s climactic moment.

Most of the extras are taken up by two commentaries: the first with “Simpsons” principal creators and players James L. Brooks, Matt Groening, Al Jean, Mike Scully, David Silverman, Dan Castellaneta and Yeardley Smith; the second with directors David Silverman, Mike B. Anderson, Steven Dean Moore and Rich Moore. There’s six deleted scenes, including one where Albert Brooks’ character, Secretary of the Interior (to President Schwarzenegger) Dean Cargill is animated as a much more milquetoast character. And there’s the “Special Stuff,” which includes Homer’s attempt at a monologue on “The Tonight Show,” and two stabs at Fox’s “American Idol” show.

Time magazine once referred to “The Simpsons” as the “Best. TV Show. Ever.” I don’t know about that, but then I’m partial to “Star Trek” myself. I don’t know as much about the show as some of my co-workers do, but I do like it when I have the chance to watch it. Which unfortunately isn’t much, but that’s what they make DVDs for.

So whether you like “The Simpsons Movie” or not depends on how much you enjoy the show. Since it did so well at the box office, I’d say there’s a guaranteed market for this disc. Or you might be the kind of person who will take Homer’s statement of disbelief at the beginning of the film to heart, and wonder why anyone would pay for something they can see on TV for free. Your call.